To test
the efficacy of phage therapy in a production-like setting, we inoculated four market-weight pigs (in three
replicates) with Salmonella enterica serovar Typhimurium and allowed the challenged pigs to contaminate a
holding pen for 48 h. Sixteen naïve pigs were randomly split into two groups which received either the
anti-Salmonella phage cocktail or a mock treatment. Both groups of pigs were comingled with the challenged
pigs in the contaminated pen. Treatment with the anti-Salmonella phage cocktail significantly reduced cecal
Salmonella concentrations (95%; P < 0.05) while also reducing (numerically) ileal Salmonella concentrations
(90%; P 0.06). Additional in vitro studies showed that the phage cocktail was also lytic against several
non-Typhimurium serovars.